# Copyright 2016 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

module Google
  module Protobuf
    # A Timestamp represents a point in time independent of any time zone
    # or calendar, represented as seconds and fractions of seconds at
    # nanosecond resolution in UTC Epoch time. It is encoded using the
    # Proleptic Gregorian Calendar which extends the Gregorian calendar
    # backwards to year one. It is encoded assuming all minutes are 60
    # seconds long, i.e. leap seconds are "smeared" so that no leap second
    # table is needed for interpretation. Range is from
    # 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z.
    # By restricting to that range, we ensure that we can convert to
    # and from  RFC 3339 date strings.
    # See {https://www.ietf.org/rfc/rfc3339.txt}[https://www.ietf.org/rfc/rfc3339.txt].
    #
    # Example 1: Compute Timestamp from POSIX +time()+.
    #
    #     Timestamp timestamp;
    #     timestamp.set_seconds(time(NULL));
    #     timestamp.set_nanos(0);
    #
    # Example 2: Compute Timestamp from POSIX +gettimeofday()+.
    #
    #     struct timeval tv;
    #     gettimeofday(&tv, NULL);
    #
    #     Timestamp timestamp;
    #     timestamp.set_seconds(tv.tv_sec);
    #     timestamp.set_nanos(tv.tv_usec * 1000);
    #
    # Example 3: Compute Timestamp from Win32 +GetSystemTimeAsFileTime()+.
    #
    #     FILETIME ft;
    #     GetSystemTimeAsFileTime(&ft);
    #     UINT64 ticks = (((UINT64)ft.dwHighDateTime) << 32) | ft.dwLowDateTime;
    #
    #     // A Windows tick is 100 nanoseconds. Windows epoch 1601-01-01T00:00:00Z
    #     // is 11644473600 seconds before Unix epoch 1970-01-01T00:00:00Z.
    #     Timestamp timestamp;
    #     timestamp.set_seconds((INT64) ((ticks / 10000000) - 11644473600LL));
    #     timestamp.set_nanos((INT32) ((ticks % 10000000) * 100));
    #
    # Example 4: Compute Timestamp from Java +System.currentTimeMillis()+.
    #
    #     long millis = System.currentTimeMillis();
    #
    #     Timestamp timestamp = Timestamp.newBuilder().setSeconds(millis / 1000)
    #         .setNanos((int) ((millis % 1000) * 1000000)).build();
    #
    #
    # Example 5: Compute Timestamp from current time in Python.
    #
    #     now = time.time()
    #     seconds = int(now)
    #     nanos = int((now - seconds) * 10**9)
    #     timestamp = Timestamp(seconds=seconds, nanos=nanos)
    # @!attribute [rw] seconds
    #   @return [Integer]
    #     Represents seconds of UTC time since Unix epoch
    #     1970-01-01T00:00:00Z. Must be from from 0001-01-01T00:00:00Z to
    #     9999-12-31T23:59:59Z inclusive.
    # @!attribute [rw] nanos
    #   @return [Integer]
    #     Non-negative fractions of a second at nanosecond resolution. Negative
    #     second values with fractions must still have non-negative nanos values
    #     that count forward in time. Must be from 0 to 999,999,999
    #     inclusive.
    class Timestamp; end
  end
end